定義： The fifth post-naupliar life stage of a copepod. All copepodid stages are characterised by two pairs of unsegmented swimming appendages, and an unsegmented "hind-body" comprising the thorax and the abdomen. (http://en.wikipedia.org/wiki/Copepodid#Copepoda)
定義： In population biology, the generation time is a quantity that reflects the average time between two consecutive generations. Reciprocal of Generation Frequency
